This application is the national phase under 35 U.S.C. xc2xa7 of PCT International Application No. PCT/JP98/00274 which has an International filing date of Jan. 23, 1998, which designated in the United States of America.
1. Technical Field
The present invention relates to a cleaning article used by impregnating a detergent for cleaning surfaces of glass, etc. More particularly, the present invention relates to a cleaning article which can release a proper amount of a detergent for each wipe and exhibit excellent detergency by controlling the amount of the impregnated detergent released to increase the utilization efficiency of the detergent and thus capable of cleaning a larger area. The present invention also relates to a detergent-impregnated article comprising the cleaning article and a detergent impregnated therein.
2. Background Art
Cleaning sheets impregnated with a detergent component are disclosed, for example, in Japanese Patent Laid-Open No. 2-84926 which corresponds to EP-A-353014 and Japanese Patent Laid-Open No. 5-15481.
Japanese Patent Laid-Open No. 2-84926 proposes a wiping article suitable for use in cleaning soiled surfaces in the presence of water, which comprises a first substrate layer, a second substrate layer, and a surface active agent in solid form held in between these two base layers. On each of the facing sides of the first and second base layers is provided with a discontinuous coating layer comprising polyethylene, which serves to retard oozing of the surface active agent in solid form out of the wiping article.
Japanese Patent Laid-Open No. 5-15481 describes a cleaner for a smooth surface, which comprises a cleaning cloth having a dirt-catching fiber layer made up of ultrafine fibers or divided fibers and a liquid-absorbing fiber layer, and a cleaning agent containing a solvent impregnated into the cloth.
These conventional cleaning articles have the following disadvantages.
The problem of the wiping article according to Japanese Patent Laid-Open No. 2-84926 is that it is incapable of cleaning a hard surface unless there is a large amount of water on the surface to be cleaned because it has no liquid detergent therein but the surface active agent in solid form that is held inside the article and is to be gradually dissolved and released by means of externally supplied water.
In the cleaner for a smooth surface disclosed in Japanese Patent Laid-Open No. 5-15481 no discussion or appreciation for gradual release of the impregnated detergent is given. Therefore, a problem is that a single wipe with the cleaner tends to release more detergent than necessary onto the surface to be cleaned and, as a result, it is difficult to clean a large area with this cleaner. The liquid-absorbent fiber layer of this cleaner comprises hydrophilic fibers such as rayon, pulp and cotton.
Accordingly, an object of the present invention is to provide a cleaning article used by impregnating a detergent which releases the detergent impregnated therein uniformly and ensures increased utilization efficiency of the detergent. Further, an object of the present invention to provide a cleaning article used by impregnating a detergent which exhibits high cleaning power over a large area with a proper amount of a detergent without using water.
As a result of extensive investigations, the present inventors have found that the above object is accomplished by a cleaning article used by impregnating a detergent comprising a detergent-retaining layer and specific detergent gradual-releasing layers, these layers being laminated in a specific structure.
The present invention has been discovered based on this finding. That is, the above object is accomplished by providing a cleaning article comprising a detergent-retaining layer containing a hydrophobic material and detergent gradual-releasing layers having a higher density than said detergent-retaining layer, said detergent-retaining layer being sandwiched between said detergent gradual-releasing layers.
The present invention is also provide a detergent-impregnated article comprising a cleaning article and a detergent impregnated in said cleaning article, said cleaning article comprising a detergent-retaining layer containing a hydrophobic material and a detergent gradual-releasing layers having a higher density than said detergent-retaining layer, said detergent-retaining layer being sandwiched between said detergent gradual-releasing layers.